Critics of T-Mobile's claim contend that its HSPA+ network shouldn't be considered either "next generation" or 4G at all. In fact, T-Mobile last summer was calling basically the same HSPA+ network "the fastest 3G network," they note.

The premiere technical body that cares about such matters, the International Telecommunication Union (ITU), recently said that all U.S. wireless networks being called 4G today aren't really 4G.

The ITU reserves that moniker for networks that achieve speeds of 100 Mbit/sec., or about 10 times the performance offered by any carrier, including T-Mobile, today.

All of the top carriers offer a range estimates of what their 4G network speeds are, or will be. At times, the carriers' estimate theoretical speeds, though analysts say a more honest approach is to use actual average speeds of both the downlink to the device and the uplink from the device to somewhere else (usually much slower).

T-Mobile lists its theoretical HSPA+ downlink speeds at up to 21 Mbit/sec., though the company said in a statement this week that the average downlink speed on the company's myTouch 4G phone is 5 Mbit/sec.

Verizon Wireless, which plans to unveil LTE 4G in 38 markets by year's end, and AT&T, which will unveil LTE 4G in 2011, project speeds ranging from 5 Mbit/sec. to 12 Mbit/sec. on a downlink. Sprint Nextel, which has WiMax 4G in 55 markets, usually claims downlink speeds of 5 Mbit/sec. to 8 Mbit/sec.

Both Sprint and AT&T criticized T-Mobile's latest claim in e-mailed comments to Computerworld, though neither company mentioned the average speeds of their networks offering.

A Sprint spokeswoman, claiming that her company was the first carrier to offer 4G, said there's more to such networks than just throughput, or speed. For example, the low latency in Sprint's network enables gaming and video chat to be run more effectively, she said.

An AT&T spokeswoman claimed that her company offers the "fastest mobile broadband network--period." Without mentioning speeds, the spokeswoman added that AT&T will have HSPA+ technology rolled out for some 250 million people by the end of November, more than the 200 million people T-Mobile claims will be within reach of its network by year's end.

The AT&T LTE network coming next year will be "even faster," she added.

Many analysts note that pure network speed is not important unless a carrier offers devices that can take advantage of 4G speeds that are generally 10 times faster than 3G.

Several analysts said users probably won't detect the difference between 5 Mbit/sec. or 12 Mbit/sec. speeds, even within a streaming video application. Other factors, such as how many users are near a cell tower, will become more important, they said.

"Unless it is 3 a.m. and you are standing next to a cell tower with nobody else awake, most devices won't hit the high advertised speed," said Jack Gold, an analyst at J. Gold Associates.

As such, analysts said consumers should learn to take advertised wireless speeds as well as claims that they offer a 4G network with a grain of salt. "A rose by any other name has just as many thorns," Gold said. "It's all market spin. The average user couldn't care less about speeds that are that much different."

Gartner analyst Phillip Redman has long criticized how T-Mobile describes the performance of its networks. On Thursday, he noted, "There are lies, damn lies and marketing. In the end the network availability, quality and price will drive success."